Storage tank and compressor assembly



March 23, 1943.

Filed Jan. 4,

J. D. BANNING ETAL STORAGE TANK AND COMPRESSOR ASSEMBLY INVENTORSZ ATTORNEYS Patented Mar. 23, 1943 STORAGE TANK ANb COMPRESSOR ASSEMBLY John D. Banning, Chicago, and Alfred Anderson,

Elrnhurst, Ill., assignors to Davidson Manufacturing Corporation, a corporation of Illinois Application January 4, 1940, Serial No. 312,432

11 Claims.

Garages and service stations heretofore have generally been provided with storage tank and air compressor assemblies for tire inflation, each including a horizontal tank with the compressor and motor mounted on beams extending along or across the tank and secured to a base on which the tank rests. Such units require considerable floor space and are unattractive in appearance. Furthermore, in many places where the law requires that the electric motor be 4 feet above the floor for safety in the presence of gasoline, a special platform is required.

According to the present invention a combination is provided which makes it possible to dispense with the unattractive and dirt-collecting beams, turn the tank to an upright position, conceal the compressor within the tank, and mount the motor above the tank where, because of the upright position of the tank, it will be the required 4 feet above floor level. At the same time high efficiency of the compressor is attained by providing a partition in the tank below the compressor to form an oil well so that the oil pump for lubricating and sealing the compressor may be submerged in oil.

Notonly does this new combination use less floor space and provide a more attractive appearance, but it also results in a considerable saving since neither the base for the tank nor the beams for supporting the motor and compressor thereon are required.

It is also possible, by such an arrangement, to eliminate the usual dome required for rotary compressors, and by suitable placement and construction of the partition between the compressor and the tank storage space, excellent separation of the oil from the air may be attained. Some of these advantages may also be obtained when the principles of this invention are applied to a horizontally disposed tank.

Additional advantages and objects will be apparent from the following description and from the drawing, in which:

Fig. 1 is a vertical sectional view of the embodiment of the invention chosen for illustration, partly broken away for the sake of clarity.

Fig.2 is a fragmentary vertical sectional view through the pump housing. 1

Fig. 3 is a fragmentary horizontal sectional view taken on the line 3-3 of Figs. 1 and 2.

A preferred form of the invention has been chosen for illustration and description, in compliance with section 4888 of the Revised Statutes, but persons skilled in the art will readily perceive other means for accomplishing the same results, and the claims are therefore to be construed as broadly as possible, consistent with the prior art.

The invention has beenillustrated as including a storage tank II, a compressor l2, and a motor I3 mounted together in an upright unit. The tank II is shaped with a concave bottom I4 to prevent its bulging under pressure and to permit the tank to rest firmly on its bottom periphery.

The compressor I2 is carried by a compressor frame l5 having an integral flange i6, which is secured to an annular rim I! surrounding an opening l8 in the top of the storage tank II. A suitable sealing gasket would of course be provided, and the flange I6 would be secured to the rim I1 by screws to permit removal of the motor and compressor unit. The compressor frame l5 includes an upper half l9 and a lower half 2| secured together by flanges 22 and suitable screws therein. The compressor I2 is assembled between the two frame halves I9 and 2|.

The compressor I2 is driven by a shaft 23 which in turn is driven through suitable flexible coupling means indicated diagrammatically at 24 by the motor I3. The compressor may be 'of any type which operates satisfactorily at the speed of the motor. To operate at this speed it is preferred that it be a type of rotary pump in which both the cylinder and the piston rotate, each about its own axis. It is inefllcient for such' a pump to be submerged in oil because the oil creates too much friction for the rotation of the cylinder.

Nevertheless, it is desirable that the surfaces of such a pump be sealed with oil as well as lubricated, and to this end it is desirable that the pump be provided with an oilpump, preferably of a positive displacement type such as that shown in Figs. 2 and 3. As seen in these figures, oil is drawn in through the inlet pipe 26 and inlet port 21 to the pumping chamber 28, which is formed in the lower frame casting 2|. A piston 29 is positioned in this chamber in tangential relationship with the peripheral wall thereof and is actuated by an'eccentrlc bearing surface at the end of pump shaft 23. A vane 3| divides the pumping chamber 28 so that, as the point of tangency rotates, oil is drawn in through inlet port 21 and then expelled through an outlet port 32 and a channel 33. The channel 33 lubricates the upper face of the piston 29 and may also communicate with channels for lubrieating the bearing for shaft 23. Port 32 communicates with suitable channels for carrying the oil pump more eillcient in operation but also ensures the presence of oil therein at all times so that, immediately .on starting the motor, oil will always be forced to the points needing lubrication and sealing. According to the present invention this is accomplished by providing a partition 38 in the tank I I positioned slightly below-the pump unit. Sufllcient oil is placed in the tank above this partition to submerge the oil pump represented by the piston 28.

As the compressor l2 rotates, it draws air in through intake pipe 38, intake conduits 39 and I0, and expels the compressed air through a suitable outlet port in the compressor l2 to the space between the compressor l2 and the frame l3. From this space the compressed air may pass freely through any suitable number of ports 42 to the upper chamber 43 above the partition 36. A pipe 44 extends through the partition to a height well above the oil level and is sealed to the partition so as to prevent the passage of oil from the upper chamber to the lower chamber, while permitting air to flow fromgrne side to the other. The pipe 44 may be provided with a guard 46 positioned above but not closing the pipe 44 to ensure against the possibility of oil splashing into the pipe 44. An outlet pipe 41 communicates with the lower portion of the tank to carry the compressed air to the points where it is to be used.

As the compressed air cools, water will often be condensed therefrom since the pipe 38 ordinarily draws in ordinary atmospheric air, the pipe only being necessary in order to locate the intake pipe at a point where the air is comparatively clean. Most of the water which condenses within the tank will possibly condense below the partition 36, where most of the cooling takes place. Accordingly, a drain valve 48 may be connected with the tank near the bottom thereof and may occasionally be opened until the water drains below the level of this valve.

Since there will be some condensation above the partition 36, it is also desirable to provide a drain valve 49 communicating immediately above this partition, unless some automatic means is provided for causing the water to drain to the lower side of the partition while retaining the oil thereabove. In order that the attendant may know when to drain off the water and may be sure to shut off the valve 49 before any oil is lost, a glass gauge 5| is provided. The gauge 5| may communicate with the tank at the three points 52, 53 and 54-one immediately above the partition 36, another within the oil zone, and a third above the oil zone. In this way the level of both the water and the oil can be seen. As illustrated, the partition 36 preferably slopes toward the drain valve 49.

Although the large area of the tank will probably make cooling fins unnecessary, they can be provided if desired, especially for the upper portion of the tank. Also the intake pipe 26 may pass from the intake screen 56 through the wall of the tank, around the tank one or more times, and back through the wall to the oil intake port 21, In this way the oil will be cooled and will help some in cooling the whole compressor. The cooling of the oil may be aided by fins 51 in conthe motor and the piston of the compressor, at least if the motor were supported directly by the upper frame casting IS. The arrangement shown is preferred. partly to elevate the motor since some safety regulations require that in the presence of gasoline the motor be at least 4 feet above the floor level. As illustrated, the motor I! may be supported by a casting 58 which in turn will be secured with upper casting is t th rim l I. The casting 58 will not only protect the shaft 23 against dirt and coupling 24 against tampering, but will also provide a neat appearing housing.

From the foregoing it is seen that a pump assembly is provided which takes up a minimum of floor space, requires no beams or platform, positions the motor a safe distance above the floor, and Provides an oil reservoir in which the oil pump is submerged so that the pump always operates with high etllciency immediately upon starting. Furthermore, considerable economy is effected by utilizing the storage tank as the oil reservoir in place of the dome which is usually provided in compressors for this purpose so that.

the-dome may be omitted. Some of the advantages of this invention will be attained even when the assembly is designed to be positioned horizontally instead of vertically, as shown. For example, with either position of the tank, the partition together with the pipe II will serve as an oil separator so that only clean air will pass out through the pipe 41.

We claim:

1. An air compressor assembly including an upright air storage tank of substantial volume having its bottom shaped to rest on a flat surface, a rotarycompressor unit carried by the top of the tank, extending into the tank and discharging into it, a motor carried by the top of the tank in axial alignment with the compressor unit and connected thereto, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil above th artition, said compressor unit including a rotary oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

2. An air compressor assembly including an upright air storage tank of substantial volume, a rotary compressor unit carried by the top of the tank, extending into the tank and discharging into it, a motor carried by the top of the tank in axial alignment with the compressor unit and connected thereto, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a bodyof oil above the partition, said compressor unit including a rotary ofl pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

3. An air compressor assembly including an upright air stora e tank of substantial volume, a rotary compressor unit carried by the top of the tank, extending into the tank and discharging into it, a motor carried by the top of the tank'and connected to the compressor unit, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil above the partition, said compressor unit including a rotary oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

4. An air compressor assembly including an upright air storage tank of substantial volume, a compressor unit carried by the top of the tank, extending into the tank and discharging into it, a motor carried by the top of the tank and connected to the compressor unit, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil above the partition, said compressor unit including an oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

5. An air compressor assembly including an air storage tank of substantial volume, a rotary compressor unit carried by the tank, extending into the tank and discharging into it, a motor carried by the tank in axial alignment with the compressor unit and connected thereto, an inclined partition positioned slightly below the com pressor unit and below the discharg thereof to maintain a body of oil above the partition, and means to remove condensation water from above the partition, said compressor unit including an oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

6. An air compressor assembly including an upright air storage tank of substantial volume having its bottom shaped to rest on a flat surface, a rotary compressor unit carried by the top of the tank and discharging into the tank, a motor carried by the top of th tank in axial alignment with the compressor unit and connected thereto, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil approximately at the level of thebottom of the unit, said compressor unit including an oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passag from above the partition to below it for the flow of air discharged from the compressor.

7. An air compressor assembly including an upright air storage tank of substantial volume, a rotary compressor unit carried by the top of the tank and discharging into the tank, a motor carried by the top of the tank in axial alignment with the compressor unit, and connected thereto, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil approximately at the level of the bottom of the unit but adapted to permit air to pass to the space below the partition. said compressor unit including an oil pump adapted to pump oil through the compressor unit from said body of oil.

8. An air compressor assembly including an upright air storage tank of substantial volume, a rotary compressor unit carried by the top of the tank and discharging into the tank, a motor carried by the top of the tank in axial alignment with the compressor unit and connected thereto, and a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil approximately at the level of the bottom of the unit, said compressor unit including an oil pump at the bottom thereof posi tioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

9. An air compressor assembly including an upright air storage tank of substantial volume, a rotary compressor unit carried by the top of the tank, extending into the tank and discharging into it, a motor carried by the top of the tank in axial alignment with the compressor unit and connected thereto, and a partition positioned slightly below the compressor unit to maintain a body of oil above the partition, said compressor unit including a rotary oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said partition having a pipe extending upwardly therefrom to permit the passage of air through the partition while preventing passage of oil therethrough.

10. An air compressor assembly including an upright air storage tank of substantial volume, a rotary compressor unit carried by the top of the tank, extending into the tank and discharging into it, a motor carried by th top of the tank in axial alignment with the compressor unit and connected thereto, a partition positioned slightly below the compressor unit and below the discharge thereof to maintain a body of oil above the partition, and means to remove condensation water from above the partition, said compressor unit including a rotary oil pump at the bottom thereof positioned below the normal oil level and drawing oil therefrom for lubricating and sealing the compressor unit, and said tank having a passage from above the partition to below it for the flow of air discharged from the compressor.

11. An air compressor assembly including a storage tank of substantial volume, a compressor unit carried by the tank, extending into the tank and discharging into it, a motor carried by the tank in axial alinement with the compressor unit and connected thereto. an apertured partition in the tank slanting upwardly from an approximately vertical wall thereof to maintain a body of oil above the partition, and means for drawing 011' foreign matter from above the partition near its bottom, whereby a relatively small volume of oil will, in the vicinity of the draw-off, be, relatively deeper than if the partition were horizontal, and means for causing oil from said body to lubricate said compressor unit.

JOHN D. BANNING. ALFRED ANDERSON. 

